Has anyone ever used a Felt Heritage for a Grubee 4-stroke?

I am wondering if anyone has ever tried to mount a Grubee 4-stroke in a Felt Heritage frame. My guess is it won't fit but I'd love to know because it seems the perfect cruiser bike in every respect - springer forks, twin V-brakes, light alloy frame so it's light and fast etc.

I have measured it using AutoCAD to scale the Fely photo but Felt give no frame geometry and I have been told the critical dimensions by someone who claims to sell them. It is too close to call - could fit by 2mm or not fit by 2mm. You HAVE to eyeball it yourself.
Southcott, the Australian importer only import 3 Felt cruisers and the Heritage isn't on that list and neither is the MP.
They could sell heaps of them if they wanted to but they can't be bothered.
They do all right as it is.
The critical dimensions on the Heritage are the distance along the top of the chain guard from the seat tube to the down tube and the height from back of chain guard at seat tube vertically to the top tube.
The former could require a specially shortened engine tray and the latter could require cutting the choke lever to shorten it. The problems are all caused because the downtube isn't goose-necked like a classic American beach cruiser frame.

The Aus government is looking at a way to shake up these fat cat sole importers through licenses and penalties for poor service because they have kept their monopolies totally unscathed right through the 30 year economic revolution.
I think they are soon going to have to work harder to keep their priviledges and I'd love to see them having to get off their backsides and compete.
Felt aren't helpful at all and the owner, Jim Felt, is probably too busy composing more ghastly poems for that terribly annoying website of his.
Has anyone ever had any help from the guys at Felt I wonder apart from helps with rhyming?